A Style is a set of appearance attributes, such as colors, brushes and images that can be applied to schedule items or calendar view cells as an integral entity. Styles support cascading propagation of attributes up through the visualization hierarchy. Attributes defined in more specific styles override the attributes defined in more general styles. If a style leaves some attribute values undefined, the ones specified in a more general style or in the current theme are used. For example, the Item.Style cascades to ItemSettings.Style, which in turn cascades to the corresponding style in the current theme. If a value in Item.Style is defined, it will be used. Otherwise, the style system will take this value from ItemSettings.Style. If the value is not present there too, it will be obtained from the current theme.

Themes are complete sets of styles and attributes that can be applied to the calendar and its views. The themes contain values for all properties in the MonthSettings, TimetableSettings, ListViewSettings, and so on, defining the appearance of the various calendar views. JPlanner comes with several predefined themes: Standard, Windows2003, Silver, Lila, and Vista. Use the Calendar.applyTheme method to apply a specific theme.

You can create custom themes by deriving from Theme. For more information on how to do this see Custom Themes.